General pre-release cleanup commit

* Rename {model,util_model}.{h,cpp} files to match class names
* Fix alreadyVisited() issue in TheoryEngine
* Remove spurious Message that causes compliance issues
* Update copyrights, fix public/private markings in headers
* minor comment fixes
* remove EXTRACT_OP as a special-case in typechecker
* note about rewriters in theoryskel readme
* Clean up some compiler warnings
* Code typos and spacing

2 files changed, 3 insertions, 3 deletions

diff --git a/src/theory/booleans/theory_bool.cpp b/src/theory/booleans/theory_bool.cpp
index 895f4a279..a809ad0e8 100644
--- a/src/theory/booleans/theory_bool.cpp
+++ b/src/theory/booleans/theory_bool.cpp
@@ -38,7 +38,7 @@ Theory::PPAssertStatus TheoryBool::ppAssert(TNode in, SubstitutionMap& outSubsti
     return PP_ASSERT_STATUS_CONFLICT;
   }
 
-  // Add the substitution from the variable to it's value
+  // Add the substitution from the variable to its value
   if (in.getKind() == kind::NOT) {
     if (in[0].getKind() == kind::VARIABLE) {
       outSubstitutions.addSubstitution(in[0], NodeManager::currentNM()->mkConst<bool>(false));
diff --git a/src/theory/booleans/theory_bool_rewriter.cpp b/src/theory/booleans/theory_bool_rewriter.cpp
index 1caa4b429..00f183eb5 100644
--- a/src/theory/booleans/theory_bool_rewriter.cpp
+++ b/src/theory/booleans/theory_bool_rewriter.cpp
@@ -147,7 +147,7 @@ RewriteResponse TheoryBoolRewriter::preRewrite(TNode n) {
       if ((*i).getKind() == kind::OR) done = false;
     }
     if (!done) {
-      return flattenNode(n, /*trivialNode = */ tt, /* skipNode = */ ff);
+      return flattenNode(n, /* trivialNode = */ tt, /* skipNode = */ ff);
     }
     break;
   }
@@ -160,7 +160,7 @@ RewriteResponse TheoryBoolRewriter::preRewrite(TNode n) {
       if ((*i).getKind() == kind::AND) done = false;
     }
     if (!done) {
-      RewriteResponse ret = flattenNode(n, /*trivialNode = */ ff, /* skipNode = */ tt);
+      RewriteResponse ret = flattenNode(n, /* trivialNode = */ ff, /* skipNode = */ tt);
       Debug("bool-flatten") << n << ": " << ret.node << std::endl;
       return ret;
     }